Transition-metal-catalyzed decarbonylation via carbon-carbon bond cleavage is an essential synthetic methodology. Given the ubiquity of carbonyl compounds, the selective decarbonylative process ...offers a distinct synthetic strategy using carbonyl groups as "traceless handles". This reaction has been significantly developed in recent years in many respects, including catalytic system development, mechanistic understanding, substrate scope, and application in the synthesis of complex functional molecules. Therefore, this review aims to summarize the recent progress on transition-metal-catalyzed decarbonylative process, from the discovery of new transformations to the understanding of reaction mechanisms, to reveal the great achievements and potentials in this field. The contents of this review are categorized by the type of chemical bond cleavage in the decarbonylative process. The main challenges and opportunities of the decarbonylative process are also examined with the goal of expanding the application range of decarbonylation reactions.
The oncogene c‐Myc is aberrantly expressed and plays a key role in malignant transformation and progression of hepatocellular carcinoma (HCC). Here, we report that c‐Myc is significantly up‐regulated ...by tumor necrosis factor receptor–associated factor 6 (TRAF6), an E3 ubiquitin ligase, in hepatocarcinogenesis. High TRAF6 expression in clinical HCC samples correlates with poor prognosis, and the loss of one copy of the Traf6 gene in Traf6+/– mice significantly impairs liver tumorigenesis. Mechanistically, TRAF6 first interacts with and ubiquitinates histone deacetylase 3 (HDAC3) with K63‐linked ubiquitin chains, which leads to the dissociation of HDAC3 from the c‐Myc promoter and subsequent acetylation of histone H3 at K9, thereby epigenetically enhancing the mRNA expression of c‐Myc. Second, the K63‐linked ubiquitination of HDAC3 impairs the HDAC3 interaction with c‐Myc and promotes c‐Myc protein acetylation, which thereby enhances c‐Myc protein stability by inhibiting carboxyl terminus of heat shock cognate 70‐kDa–interacting protein–mediated c‐Myc ubiquitination and degradation. Importantly, TRAF6/HDAC3/c‐Myc signaling is also primed in hepatitis B virus–transgenic mice, unveiling a critical role for a mechanism in inflammation–cancer transition. In clinical specimens, TRAF6 positively correlates with c‐Myc at both the mRNA and protein levels, and high TRAF6 and c‐Myc expression is associated with an unfavorable prognosis, suggesting that TRAF6 collaborates with c‐Myc to promote human hepatocarcinogenesis. Consistently, curbing c‐Myc expression by inhibition of TRAF6 activity with a TRAF6 inhibitor peptide or the silencing of c‐Myc by small interfering RNA significantly suppressed tumor growth in mice. Conclusion: These findings demonstrate the oncogenic potential of TRAF6 during hepatocarcinogenesis by modulating TRAF6/HDAC3/c‐Myc signaling, with potential implications for HCC therapy.
Gaussian boson sampling (GBS) plays a crucially important role in demonstrating quantum advantage. As a major imperfection, the limited connectivity of the linear optical network weakens the quantum ...advantage result in recent experiments. In this work, we introduce an enhanced classical algorithm for simulating GBS processes with limited connectivity. It computes the loop Hafnian of an
symmetric matrix with bandwidth w in
time. It is better than the previous fastest algorithm which runs in
time. This classical algorithm is helpful on clarifying how limited connectivity affects the computational complexity of GBS and tightening the boundary for achieving quantum advantage in the GBS problem.
We report here cobalt-
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-heterocyclic carbene catalytic systems for the intramolecular decarbonylative coupling through the chelation-assisted C-C bond cleavage of acylindoles and diarylketones. The ...reaction tolerates a wide range of functional groups such as alkyl, aryl, and heteroaryl groups, giving the decarbonylative products in moderate to excellent yields. This transformation involves the cleavage of two C-C bonds and formation of a new C-C bond without the use of noble metals, thus reinforcing the potential application of decarbonylation as an effective tool for C-C bond formation.
A method for cobalt-
N
-heterocyclic carbene catalytic systems for the intramolecular decarbonylative coupling of ketones was achieved.
The development of a direct vinylogous Michael addition of linear nucleophilic substrates is a long‐standing challenge because of the poor reactivity and the considerable difficulty in controlling ...regioselectivity. By employing a rationally designed multifunctional supramolecular iminium catalysis strategy, the first direct vinylogous Michael addition of unmodified linear substrates to α,β‐unsaturated aldehydes, to afford chiral 1,7‐dioxo compounds with good yields and excellent regio‐ as well as enantioselectivity, has been developed.
Fall into line: The title catalysis strategy was developed for addressing the long‐standing problem of the direct vinylogous Michael addition of unmodified linear dienol substrates. The desired 1,7‐dioxo compounds were obtained with good yields and excellent regio‐ and enantioselectivity. DCE=1,2‐dichloroethane, TMS=trimethylsilyl.
Polymorphism (and its extended form – pseudopolymorphism) in solids is ubiquitous in mineralogy, crystallography, chemistry/biochemistry, materials science, and the pharmaceutical industries. Despite ...the difficulty of controlling (pseudo‐)polymorphism, the realization of specific (pseudo‐)polymorphic phases and associated boundary structures is an efficient route to enhance material performance for energy conversion and electromechanical applications. Here, this work applies the pseudopolymorphic phase (PP) concept to a thermoelectric copper sulfide, Cu2‐xS (x ≤ 0.25), via CuBr2 doping. A peak ZT value of 1.25 is obtained at 773 K in Cu1.8S + 3 wt% CuBr2, which is 2.3 times higher than that of a pristine Cu1.8S sample. Atomic‐resolution scanning transmission electron microscopy confirms the transformation of pristine Cu1.8S low digenite into PP‐engineered high digenite, as well as the formation of (semi‐)coherent interfaces between different PPs, which is expected to enhance phonon scattering. The results demonstrate that PP engineering is an effective approach for achieving improved thermoelectric performance in Cu‐S compounds. It is also expected to be useful in other materials.
A material consisting of the same substance can crystalize in different structural phases with (or without) identical composition, termed “(pseudo)polymorphic phases” (PPs). This work applies this PP concept to copper sulfides to improve thermoelectric performance. The resulting PPs maintain electron transport and enhance phonon scattering. A peak ZT value of 1.25 is obtained, which is 2.3 times higher than that of pristine copper sulfide.
Background and objective
Thyroid cancer (TC) is the most common endocrine system tumour. Several studies had revealed the potential of circulating microRNAs (miRNAs) as novel biomarkers for the ...diagnosis of TC. The purpose of this meta‐analysis is to summarize published studies and evaluate the diagnostic accuracy of circulating miRNAs in TC detection.
Methods
In this meta‐analysis, we systematically searched three databases: PubMed, EMBASE and Cochrane Library. We used the bivariate mixed‐effects regression model to calculate the pooled diagnostic parameters and conduct the summary receiver operator characteristic curve (SROC). All calculations were performed using stata software.
Results
Thirty‐five studies from 9 articles, including 663 TC patients, 519 patients with benign thyroid nodules (BTNs), and 84 healthy controls were included in this meta‐analysis. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and area under the SROC curve (AUC) were 0.81 (95% CI 0.75‐0.86), 0.81 (95% CI 0.75‐0.86), 4.3 (95% CI 3.2‐5.6), 0.24 (95% CI 0.18‐0.31), 18 (95% CI 12‐28) and 0.88 (95% CI 0.85‐0.90), respectively in BTN controls, and 0.81 (95% CI 0.75‐0.86), 0.85 (95% CI 0.75‐0.91), 5.3 (95% CI 3.3‐8.7), 0.23 (95% CI 0.18‐0.29), 24 (95% CI 14‐39), 0.89 (95% CI 0.86‐0.91) in healthy controls. The subgroup analysis found that multiple miRNA assays had higher diagnostic accuracy than single miRNA assays with sensitivity of 0.88, specificity of 0.89 and AUC of 0.94.
Conclusion
Circulating miRNAs have good values to diagnose TC and distinguish TC patients from BTN patients. MiRNAs can assist in the diagnosis of malignancy and avoid unnecessary surgery. In summary, circulating miRNAs should be added to our current clinical tools.
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A novel approach to 1,3oxazin-1-ones from 1,1-disubstituted alkene and N,O-acetals through scandium trifluoromethanesulfonate as catalyst in dichloroethane at 60 °C. The structure of ...this product is easily accessible. This protocol merits several advantages, such as very gentle conditions, cheap starting materials, and high yields. Altogether, 22 cases were investigated, and all the products were confirmed by spectrum methods. Three compounds were performed single crystal diffraction. The diastereochemistry was also studied in several cases.
We describe a method for intramolecular desulfonylative coupling using bis(cyclooctadiene)nickel as a catalyst. A broad range of aromatic, heteroaromatic and aliphatic sulfones can be utilized as ...substrates in this process. This method provides an atom‐economical route to the synthesis of various biaryls and an efficient tool for the catalytic conversion of sulfonyl groups, representing a significant advancement in organic synthesis
Hepatic stellate cells (HSCs) play an important role in the initiation and development of liver fibrogenesis, and abnormal glucose metabolism is increasingly being considered a crucial factor ...controlling phenotypic transformation in HSCs. However, the role of the factors affecting glycolysis in HSCs in the experimental models of liver fibrosis has not been completely elucidated. In this study, we showed that glycolysis was significantly enhanced, while the expression of brain and muscle arnt-like protein-1 (Bmal1) was downregulated in fibrotic liver tissues of mice, primary HSCs, and transforming growth factor-β1 (TGF-β1)-induced LX2 cells. Overexpression of Bmal1 in TGF-β1-induced LX2 cells blocked glycolysis and inhibited the proliferation and phenotypic transformation of activated HSCs. We further confirmed the protective effect of Bmal1 in liver fibrosis by overexpressing Bmal1 from hepatic adeno-associated virus 8 in mice. In addition, we also showed that the regulation of glycolysis by Bmal1 is mediated by the isocitrate dehydrogenase 1/α-ketoglutarate (IDH1/α-KG) pathway. Collectively, our results indicated that a novel Bmal1-IDH1/α-KG axis may be involved in regulating glycolysis of activated HSCs and might hence be used as a therapeutic target for alleviating liver fibrosis.
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